The Siemens 3VA1112-4EF32-0CC0 is a SENTRON molded case circuit breaker (MCCB) for line protection, rated 125 A at 40 °C across three poles. It delivers 121 kA breaking capacity at 240 V AC, stepping down to 75.6 kA at 415 V and 52.5 kA at 440 V — numbers that tell you this breaker handles high-fault utility feeds or transformer secondaries without cascading upstream. The 70 mm depth and 76.2 mm width fit standard Siemens 3VA panel cutouts, so a swap into an existing SENTRON lineup needs no enclosure rework.
Current ratings and thermal derating
Rated 125 A continuously at ambient up to 50 °C. Above that the thermal trip starts pulling back: 122 A at 55 °C, 120 A at 60 °C, 117 A at 65 °C, 114 A at 70 °C. If your panel runs hot — say a sealed enclosure near a furnace line — plan for the 114 A ceiling at 70 °C rather than the nameplate 125 A.
Breaking capacity across voltage levels
The 121 kA at 240 V is the headline number, but the real-world SCCR you care about for a 400 V panel is 75.6 kA at 415 V. At 500 V and 690 V it holds 11.9 kA — enough for most motor branch circuits but not for a main feeder at those voltages. Rated insulation voltage is 800 V, so the breaker itself is insulated for 690 V systems.
Auxiliary and release options
Factory-fitted with 2 auxiliary switches (HQ type) and an undervoltage release (UVR). The UVR trips the breaker when control voltage drops — standard for emergency-stop circuits or undervoltage protection on motor starters. No ground-fault module, no communication function, no voltage trip indicator. If you need shunt trip or ground-fault, this isn't the variant.
Physical fit and environment
Dimensions: 130 mm height, 76.2 mm width, 70 mm depth. Mounts on a DIN rail or direct panel-mount in the standard 3VA footprint. Operating temperature range -25 °C to 70 °C; storage from -40 °C to 80 °C. Power dissipation max 30.6 W — factor that into enclosure thermal calculations if you're packing several breakers in a small box.